The Role of Nano-domains in {1–011} Twinned Martensite in Metastable Titanium Alloys

Abstract

The formation mechanism of { 1¯011} α′ type twinned α′-martensitic structures was investigated in titanium alloys, and in-depth characterizations of the microstructures were performed using scanning electron microscopy and transmission electron microscopy. The randomly distributed nano-domains nucleated by water quenching were sheared during the primary martensite transformation. Experimental results revealed that this sheared nano-domain interferes with the primary martensite transformation and induces a secondary martensite transformation. In terms of crystallography, the secondary martensite transformed from the sheared nano-domain has a { 1¯011} α′ type twin relationship with the primary martensite. The growth of both martensites yielded a more twinned martensitic structure as the applied strain increased.